Tuesday, July 20, 2021

With most paving complete, Revive I-5 shifts to expansion joints

UPDATE Thursday, July 22: The next scheduled Revive I-5 weekend closure - July 30 to Aug. 2 - has been canceled. Be sure to check the project website linked below for updates on the schedule.

By Tom Pearce

This past weekend our contractor finished most grinding and paving portions of our Revive I-5 project on the southbound freeway between I-90 and Spokane Street in Seattle. Crews began by grinding I-5 to smooth the surface during overnight shifts. During two weekends when lanes were reduced, they repaved a thin layer of polyester concrete, which is more durable than regular concrete.

We have repaved about 1¼ miles of all lanes of this section of southbound I-5, which has anywhere from three to five lanes. With the paving mostly finished, now we’ll turn our attention to expansion joints in the same section of freeway. 

No easy task replacing 56 expansion joints

This part of the freeway is built on piers like a bridge, so it has 40 expansion joints that allow it to expand and contract with weather changes. If you drive this section very often, you know the joints need to be replaced. In addition to the occasional bump or metallic clunking sound you may encounter, we’ve had several break in the past few months, requiring emergency repairs on weekday mornings or afternoons. That creates unplanned backups and delays.

When an expansion joint breaks, we have to repair it right away regardless of traffic and time of day.

In addition to those on the main section of the highway, we have 16 other expansion joints to replace on ramps that serve this part of the freeway. Replacing just half of a joint takes an entire weekend. We’ll do several halves during each closure, but it’s going to take at least 14 more weekends between now and summer 2022 to replace all of them.

Why so long?

Yes, that makes for a long project, but there are several factors. First is events in Seattle. When a weekend sporting event or concert brings an additional 35,000 to 65,000 people to the area, it’s very difficult to schedule work.

Then there’s the material – when we replace these expansion joints, we’ll use the more durable polyester concrete. But that limits working conditions – it needs to be more than 50 degrees Fahrenheit and completely dry to pave this type of concrete.

Polyester concrete is more durable but it requires dry weather and moderate temperatures.

We also need to plan ahead for this work to be sure we can get the materials we need and let you know we’re going to work. The weather, materials and notification time pretty much eliminate working during the winter as well as much of the spring and fall.

Stay looped in to the project schedule by checking the website. You can find info about the next weekend closure – July 30 to Aug. 2 – on the project page.

I’m always looking for a silver lining. For this project, while we’ll be working a lot of weekends, we’re going to wrap up most of the weeknight work by early August. A lot of people think the freeway is empty at night. I can guarantee you it is not – when night work creates backups, I hear from people who drive then. Besides, it’s not practical to replace expansion joints during overnight shifts – it would take much longer and final product would not be as strong.

We know that weekend lane reductions are hard on a lot of people. At least this way, you can plan around the work, unlike when a joint suddenly breaks and we need to do an emergency repair. Thanks for your patience!